* fix: use `--upgrade` rather than `--ignore-installed` to upgrade pip
This removes left over files when upgrading pip.
* remove all installed python on macOS
* fix: error out on install failure in "Apply build artifact to the local machine" step
* fix: error out on pip installation / update failure
* fix: use environment variable for `PIP_ROOT_USER_ACTION`
This extends the fix from #259 since every platform for 3.8.10 / 3.9.13 has been rebuilt instead of just macOS arm64 being added.
The regression was introduced in #223
The macOS pkg installer does not setup default certificates for OpenSSL.
A script is provided by the macOS pkg installer to setup those using the certifi PyPI package.
Let's run this script as part of the setup template in order to be able to do HTTPS downloads out of the box.